Odor identification predicts the transition of patients with isolated RBD: A retrospective study
Abstract Introduction To determine if the severity of olfactory dysfunction in isolated REM sleep behavior disorder (IRBD) predicts conversion to Parkinson's disease (PD) or dementia with Lewy bodies (DLB). Methods Olfaction was tested using the Japanese version of the University of Pennsylvani...
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| Format: | Article |
| Language: | English |
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Wiley
2022-08-01
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| Series: | Annals of Clinical and Translational Neurology |
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| Online Access: | https://doi.org/10.1002/acn3.51615 |
| _version_ | 1811215255549771776 |
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| author | Tomoyuki Miyamoto Masayuki Miyamoto |
| author_facet | Tomoyuki Miyamoto Masayuki Miyamoto |
| author_sort | Tomoyuki Miyamoto |
| collection | DOAJ |
| description | Abstract Introduction To determine if the severity of olfactory dysfunction in isolated REM sleep behavior disorder (IRBD) predicts conversion to Parkinson's disease (PD) or dementia with Lewy bodies (DLB). Methods Olfaction was tested using the Japanese version of the University of Pennsylvania Smell Identification Test (UPSIT‐J) in 155 consecutive patients with polysomnography‐confirmed IRBD and 34 healthy controls. IRBD patients were followed up for 5.8 ± 3.2 (range 0.2–11) years. Thirty‐eight patients underwent repeat UPSIT‐J evaluation at 2.7 ± 1.3 years after the baseline test. Results UPSIT‐J score was lower in IRBD patients than in age‐ and sex‐matched controls. The receiver operating characteristic curve analysis showed that the optimal cutoff score of 22.5 in UPSIT‐J discriminated between IRBD patients and controls with a sensitivity of 94.3% and specificity of 81.8%. Anosmia (UPSIT‐J score < 19) was present in 54.2% of IRBD patients. In total, 42 patients developed a neurodegenerative disease, of whom 17 had PD, 22 DLB, and 3 MSA. Kaplan–Meier analysis showed that the short‐term risk of Lewy body disease (LBD) was higher in patients with anosmia than in those without anosmia. At baseline, the UPSIT‐J score was similar between patients who developed PD and DLB (p = 0.136). All three IRBD patients (100%) who developed MSA did not have anosmia. Conclusions In IRBD patients, anosmia predicts a higher short‐term risk of transition to LBD but cannot distinguish between PD and DLB. At baseline, preserved odor identification may occur in latent MSA. Future IRBD neuroprotective trials should evaluate anosmia as a marker of prodromal LBD. |
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| format | Article |
| id | doaj.art-9db8bce3ba0f4e7fab2e01e95db3d427 |
| institution | Directory Open Access Journal |
| issn | 2328-9503 |
| language | English |
| last_indexed | 2024-04-12T06:19:25Z |
| publishDate | 2022-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Annals of Clinical and Translational Neurology |
| spelling | doaj.art-9db8bce3ba0f4e7fab2e01e95db3d4272022-12-22T03:44:22ZengWileyAnnals of Clinical and Translational Neurology2328-95032022-08-01981177118510.1002/acn3.51615Odor identification predicts the transition of patients with isolated RBD: A retrospective studyTomoyuki Miyamoto0Masayuki Miyamoto1Department of Neurology Dokkyo Medical University Saitama Medical Center JapanDepartment of Neurology Center of Sleep Medicine, Dokkyo Medical University JapanAbstract Introduction To determine if the severity of olfactory dysfunction in isolated REM sleep behavior disorder (IRBD) predicts conversion to Parkinson's disease (PD) or dementia with Lewy bodies (DLB). Methods Olfaction was tested using the Japanese version of the University of Pennsylvania Smell Identification Test (UPSIT‐J) in 155 consecutive patients with polysomnography‐confirmed IRBD and 34 healthy controls. IRBD patients were followed up for 5.8 ± 3.2 (range 0.2–11) years. Thirty‐eight patients underwent repeat UPSIT‐J evaluation at 2.7 ± 1.3 years after the baseline test. Results UPSIT‐J score was lower in IRBD patients than in age‐ and sex‐matched controls. The receiver operating characteristic curve analysis showed that the optimal cutoff score of 22.5 in UPSIT‐J discriminated between IRBD patients and controls with a sensitivity of 94.3% and specificity of 81.8%. Anosmia (UPSIT‐J score < 19) was present in 54.2% of IRBD patients. In total, 42 patients developed a neurodegenerative disease, of whom 17 had PD, 22 DLB, and 3 MSA. Kaplan–Meier analysis showed that the short‐term risk of Lewy body disease (LBD) was higher in patients with anosmia than in those without anosmia. At baseline, the UPSIT‐J score was similar between patients who developed PD and DLB (p = 0.136). All three IRBD patients (100%) who developed MSA did not have anosmia. Conclusions In IRBD patients, anosmia predicts a higher short‐term risk of transition to LBD but cannot distinguish between PD and DLB. At baseline, preserved odor identification may occur in latent MSA. Future IRBD neuroprotective trials should evaluate anosmia as a marker of prodromal LBD.https://doi.org/10.1002/acn3.51615Dementia with Lewy bodiesLewy body diseaseParkinson's diseaseREM sleepbehavior disorder, UPSIT‐40. |
| spellingShingle | Tomoyuki Miyamoto Masayuki Miyamoto Odor identification predicts the transition of patients with isolated RBD: A retrospective study Annals of Clinical and Translational Neurology Dementia with Lewy bodies Lewy body disease Parkinson's disease REM sleep behavior disorder, UPSIT‐40. |
| title | Odor identification predicts the transition of patients with isolated RBD: A retrospective study |
| title_full | Odor identification predicts the transition of patients with isolated RBD: A retrospective study |
| title_fullStr | Odor identification predicts the transition of patients with isolated RBD: A retrospective study |
| title_full_unstemmed | Odor identification predicts the transition of patients with isolated RBD: A retrospective study |
| title_short | Odor identification predicts the transition of patients with isolated RBD: A retrospective study |
| title_sort | odor identification predicts the transition of patients with isolated rbd a retrospective study |
| topic | Dementia with Lewy bodies Lewy body disease Parkinson's disease REM sleep behavior disorder, UPSIT‐40. |
| url | https://doi.org/10.1002/acn3.51615 |
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